Prolonged occupational exposure leads to allergic airway sensitization and chronic airway and systemic inflammation in professional firefighters.

BACKGROUND AND OBJECTIVES: Little data exist on short- and long-term effects of occupational exposure on airway and systemic inflammation in professional firefighters. We aimed to characterize airway and systemic inflammation in training firefighters with a maximum occupational exposure of 1 year compared to the long-term exposure of professional firefighters.

METHODS: A questionnaire for symptoms and exposure, pulmonary function, atopy, bronchial hyper-responsiveness, and markers of inflammation in induced sputum, serum, bronchoalveolar lavage (BAL) fluid and bronchial biopsies were assessed in a total of 92 firefighters (63 full-time professionals and 29 trainees).

RESULTS: Professional firefighters showed allergic bronchial sensitization documented by the presence of atopy, and eosinophilia in induced sputum, BAL and bronchial biopsies. IL-8, ECP, VEGF, and TNF-α levels were statistically significantly higher in the sputum supernatants of professional firefighters compared to the trainees (p = 0.04, p = 0.02, p = 0.04, and p = 0.02, respectively). Serum IL-8 and TNF-α levels were also statistically significantly higher in the group of professional firefighters (p = 0.04, p = 0.03, respectively). Finally, there was a linear correlation between the duration of the occupation in Service and the degree of airway and systemic inflammation.

CONCLUSIONS: These results indicate a "dose-response" effect of chronic exposure to a polluted environment on bronchial and systemic inflammation in professional firefighters.